The present invention relates generally to gas turbine engine endwall features, and more specifically to endwall configurations that reduce main gas path flow ingestion into secondary, lower-temperature regions of the gas turbine engine.
Gas turbine engines operate according to a continuous-flow, Brayton cycle. A compressor section pressurizes an ambient air stream, fuel is added and the mixture is burned in a central combustor section. The combustion products expand through a turbine section where bladed rotors convert thermal energy from the combustion products into mechanical energy for rotating one or more centrally mounted shafts. The shafts, in turn, drive the forward compressor section, thus continuing the cycle. Gas turbine engines are compact and powerful power plants, making them suitable for powering aircraft, heavy equipment, ships and electrical power generators. In power generating applications, the combustion products can also drive a separate power turbine attached to an electrical generator.
Seals are required in many locations within a gas turbine engine to regulate air flow to various portions of the engine. One function of air seals in gas turbine engines is to limit ingestion of hot “core” or “main” gas path airflow into secondary cavities and passages. Secondary airflow system components are often constructed to tolerate lower maximum temperatures than core gas path components. Excessive ingestion of main gas path airflow can result in undesirable heating of engine components, reducing part lifetimes or necessitating that parts be constructed of expensive, high temperature-capable materials.